I got clobbered by an 80 mph gust once just outside of work. It wasn't that windy when I started 10 miles to the east and the wind was strong enough that I was in my lowest gear (22/34) and it picked up pebbles from the ground and sandblasted me. The weather station at my work recorded the speed.

I've had lots of 50 mph tailwinds (and too many crosswinds) along the Colorado Front Range. You kind of know when the wind hits 50 because the power lines turn into Aeolian harps at about 50 mph. They have a very special sound at that speed.